About Gallatin County
Gallatin County lies in the beautiful mountains Montana, bordering Yellowstone National Park, and including the town of West Yellowstone, one of the major tourist access points to the park. It includes the point where the Wyoming, Idaho and Montana borders intersect. Gallatin County is tall and skinny with Madison Valley lies in the southern end of the county, and Gallatin Valley in the northern end. Most of the county’s 89,513 residents live in Gallatin Valley. Gallatin County covers 2,632 square miles. It was founded in 1864 and Bozeman is the county seat.
The Gallatin River were named after Albert Gallatin, who was the U.S. Secretary of the Treasury from 1801 to 1804. The river was named in 1805 by Mariwether Lewis, and the county was named after the river in 1864.
With heavy mountain snows in the winter, Gallattn County has numerous important rivers flowing through it. The Madison River crosses the southern tip of the county, passing into Madison County, and then crosses back into the northern end of Gallatin County. The Gallatin River flows out of Yellowstone, and northward through the mountains until it reaches the Gallatin Valley. The Jefferson River flows from the west into the north end of the county, and the three rivers meet at Three Forks. That marks the beginning of the Missouri River. It flows northward from Three Forks. The Madison Mountains are on the county's western border, and the Gallatin Mountains on the east. The Bridger Range is in the northeast, bordering Gallatin Valley. The Continental Divide forms the southern boundary.
Interstate 90 passes through Gallatin Valley and Bozeman, heading east and west. U.S. Highway 191 heads north and south through Gallatin County, connecting from West Yellowstone to Bozeman through the canyon of the Gallatin River. U.S. Highway 20 heads west a short distance from West Yellowstone before crossing into Idaho. U.S Highway 287 breaks off of Highway 191 not far from West Yellowstone and heads west following the Madison River.